Heavy machines may be used to demolish tough material, such as concrete and rock. One example of such a heavy machine may include an excavator equipped with a hydraulic hammer assembly. The hydraulic hammer assembly may be attached at an end of a movable arm of the excavator and connected to the hydraulic system of the excavator. In a typical configuration, the hydraulic hammer assembly may include a hydraulic hammer and a work tool secured partially within the hydraulic hammer. The hydraulic hammer may include a reciprocating piston that is driven by high pressure fluid from the hydraulic system. The reciprocating piston may impact the work tool and the force of the reciprocating piston may be imparted to the material to be demolished via the work tool.
Since the work tool is the part of the hydraulic hammer assembly through which the impact forces of the hydraulic hammer are passed to the material, the work tool may experience significant wear. Accordingly, it may be necessary for the work tool to be efficiently replaced in situ at the worksite, possibly with limited access to other tools or equipment.
U.S. Pat. No. 4,858,701 to Weyer (the '701 patent) purports to provide one system of securing a tool within a hydraulic hammer. The '701 patent discloses a hammer with a lock collar positioned at the opening of the hammer. The lock collar is configured with longitudinally extending lock collar splines with a circumferential size and spacing corresponding to drive shaft splines situated in a drive shaft bore. When a tool shank fitted with tool shank splines is inserted into the drive shaft bore such that the tool shank splines mesh with the drive shaft splines, the lock collar may be rotated into a locked position in which the lock collar splines are misaligned with the drive shaft splines. Due to the exposed positioning of the lock collar at the opening of the hammer (i.e., the bottommost portion of the hammer) and the generally violent nature of hydraulic hammer demolition, the system disclosed in the '701 patent may suffer from poor durability. These and other shortcomings are addressed in the present disclosure.